/* $Id: SetPropertyRule.java 565464 2007-08-13 18:13:47Z remm $
 *
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.tomcat.util.digester;

import org.apache.tomcat.util.IntrospectionUtils;
import org.xml.sax.Attributes;

/**
 * Rule implementation that sets an individual property on the object at the top
 * of the stack, based on attributes with specified names.
 */

public class SetPropertyRule extends Rule {

	// ----------------------------------------------------------- Constructors

	/**
	 * Construct a "set property" rule with the specified name and value
	 * attributes.
	 * 
	 * @param digester
	 *            The digester with which this rule is associated
	 * @param name
	 *            Name of the attribute that will contain the name of the
	 *            property to be set
	 * @param value
	 *            Name of the attribute that will contain the value to which the
	 *            property should be set
	 * 
	 * @deprecated The digester instance is now set in the
	 *             {@link Digester#addRule} method. Use
	 *             {@link #SetPropertyRule(String name, String value)} instead.
	 */
	public SetPropertyRule(Digester digester, String name, String value) {

		this(name, value);

	}

	/**
	 * Construct a "set property" rule with the specified name and value
	 * attributes.
	 * 
	 * @param name
	 *            Name of the attribute that will contain the name of the
	 *            property to be set
	 * @param value
	 *            Name of the attribute that will contain the value to which the
	 *            property should be set
	 */
	public SetPropertyRule(String name, String value) {

		this.name = name;
		this.value = value;

	}

	// ----------------------------------------------------- Instance Variables

	/**
	 * The attribute that will contain the property name.
	 */
	protected String name = null;

	/**
	 * The attribute that will contain the property value.
	 */
	protected String value = null;

	// --------------------------------------------------------- Public Methods

	/**
	 * Process the beginning of this element.
	 * 
	 * @param attributes
	 *            The attribute list of this element
	 * 
	 * @exception NoSuchMethodException
	 *                if the bean does not have a writeable property of the
	 *                specified name
	 */
	public void begin(Attributes attributes) throws Exception {

		// Identify the actual property name and value to be used
		String actualName = null;
		String actualValue = null;
		for (int i = 0; i < attributes.getLength(); i++) {
			String name = attributes.getLocalName(i);
			if ("".equals(name)) {
				name = attributes.getQName(i);
			}
			String value = attributes.getValue(i);
			if (name.equals(this.name)) {
				actualName = value;
			} else if (name.equals(this.value)) {
				actualValue = value;
			}
		}

		// Get a reference to the top object
		Object top = digester.peek();

		// Log some debugging information
		if (digester.log.isDebugEnabled()) {
			digester.log.debug("[SetPropertyRule]{" + digester.match + "} Set "
					+ top.getClass().getName() + " property " + actualName
					+ " to " + actualValue);
		}

		// Set the property (with conversion as necessary)
		if (!digester.isFakeAttribute(top, actualName)
				&& !IntrospectionUtils
						.setProperty(top, actualName, actualValue)
				&& digester.getRulesValidation()) {
			digester.log.warn("[SetPropertyRule]{" + digester.match
					+ "} Setting property '" + name + "' to '" + value
					+ "' did not find a matching property.");
		}

	}

	/**
	 * Render a printable version of this Rule.
	 */
	public String toString() {

		StringBuffer sb = new StringBuffer("SetPropertyRule[");
		sb.append("name=");
		sb.append(name);
		sb.append(", value=");
		sb.append(value);
		sb.append("]");
		return (sb.toString());

	}

}
